AB0620 IMMUNE THROMBOCYTOPENIC PURPURA AND SUBSEQUENT DEVELOPMENT OF SYSTEMIC LUPUS ERYTHEMATOSUS
Authors: G. Alle, M. Scolnik, V. Scaglioni, J. F. Jaramillo Gallego, M. A. Tobar Jaramillo, R. N. Alvarado, E. Soriano, J. Rosa
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Immune Thrombocytopenic Purpura (ITP) is an immune-mediated disorder, characterized by isolated thrombocytopenia (&lt;100,000/mm<sup>3</sup>). It is part of Systemic Lupus Erythematosus (SLE) classification criteria, and may be one of the first manifestations of the disease, often occurring years before its diagnosis. <h3>Objectives</h3> To assess the incidence of SLE in a cohort of patients with ITP, and to identify predictors for its development. <h3>Methods</h3> Retrospective cohort study. We included patients with ITP treated in a University Hospital between 2000 and 2018, with at least one year of follow-up. Patients with SLE or other secondary causes of ITP were excluded. Demographic, clinical, laboratory and treatment data were recorded. Patients meeting SLE classification criteria (ACR 1997/ SLICC 2012) during the follow-up were identified, and incidence density of SLE was calculated. Patients with ITP were grouped according to the development or non-development of SLE, and comparisons were made. Univariate analysis was performed to identify factors associated with the future development of SLE. <h3>Results</h3> 186 patients were included, 64.5% women, with a median age of 27.2 years (IQR 6.3-63.9). After a follow-up of 1801.4 person/years (py), 10 patients (5.4%) developed SLE, with a median time of 22.9 months (IQR 9.8-60.9) between ITP diagnosis and development of SLE. The incidence density of SLE was 5.6/1000 py (95% CI 2.9-9.9/1000 py). Patients who developed SLE had significantly higher proportion of chronic ITP (80% vs 40.3%; p 0.01), lower proportion of complete response (10% vs 54.6%; p 0.006), and more relapses (60% vs 30.6%; p 0.05). The median duration of ITP in SLE patients was significantly longer (67.5 vs 4 months, p&lt;0.001). The presence of ANA (p&lt;0.001), nuclear homogeneous pattern (p&lt;0.001), ANA titres &gt;1/640 (p 0.02), hypocomplementemia (p&lt;0.001), LAC (p&lt;0.001), hypergammaglobulinemia (p&lt;0.001), leukopenia (p 0.006) and hemolytic anemia (p 0.005) were significantly associated with the future development of SLE. <h3>Conclusion</h3> In this cohort of ITP patients, the more refractory course of ITP, as well as the presence of high titre - nuclear homogeneous ANA, hypocomplementemia, LAC, hypergammaglobulinemia and other cytopenias were associated with the subsequent development of SLE. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Gelsomina Alle: None declared, Marina Scolnik Speakers bureau: GSK, Janssen, Pfizer, Roche, Lilly, Grant/research support from: Janssen, GSK, Valeria Scaglioni: None declared, JOHN FREDY JARAMILLO GALLEGO: None declared, Mayra Alejandra Tobar Jaramillo: None declared, Rodolfo Nicolas Alvarado: None declared, Enrique Soriano Speakers bureau: Amgen, Abbvie, BMS, Eli Lilly, Janssen, Novartis, Pfizer, Sandoz, UCB, Consultant of: Abbvie, Janssen, Pfizer, Amgen, Sandoz, Novartis, Grant/research support from: Novartis, Pfizer, Amgen, Elea, Javier Rosa Speakers bureau: Eli Lilly, AbbVie/Abbott, Bristol-Myers Squibb(BMS), Amgen, Novartis, Pfizer.